Manufacture of a carbon-fabric-reinforced polyetherimide (CF/PEI) composite material

Relationships between impregnation mechanisms, consolidation quality and the resulting mechanical properties of carbon-fibre-fabric reinforced polyetherimide (CF/PEI) thermoplastic composites have been investigated. A compression-moulding procedure was applied to simulate the effects of different processing conditions (i.e. pressure, holding time and processing temperature) on the quality of finished samples. Microscopic studies of cross-sections, density measurements and flexural mechanical properties were used to examine the quality of impregnation and concolidation. A qualitative model to describe the impregnation and consolidation processes of this material was developed. It predicts the variations of void content during consolidation, as well as the holding time, moulding temperature and pressure required to reach full consolidation. Good agreement between theoretical predictions and experimental data indicates the success of the approach. Finally, aileron ribs for a civil aircraft were successfully manufactured from the CF/PEI material according to the suggested optimum processing conditions.